Getting Tanked

Nov. 1, 2010

“The next world war will be over water, not oil,” boldly states Michael Gauthier, director of marketing for Highland Tank, one of the nation’s premier steel tank manufacturers located in Stoystown, PA. “We take it for granted, but water is a finite resource, and replenishing aquifers and streams is difficult. Floods contaminate fresh water supplies; the West understands that. Wars will be fought over water.”

We shouldn’t panic, cautions Joel Portmann, president of United Tank Systems LLC, Stockbridge, WI, but we need to gain a better understanding of the clean water shortage.

We use it for “everything,” claims David Heiman, marketing communications manager at Containment Solutions Inc., in Conroe, TX—and because it’s in such demand, water rates are going up 30 to 100%.

Portmann lists some of the current uses: human consumption, fire protection, manufacturing, irrigation, aquaculture (such as fish farms), and recycling.

Because it’s in short supply in some places, certain areas are experiencing a “political drought,” which imposes water restrictions, claims Eddie Van Giesen, policy coordinator for Blue Ridge Atlantic Enterprises in Oak Boro, NC. “Water is fundamental to civilization, but we are losing fresh water to saline every year at a phenomenal amount,” he points out, which is probably why “our oldest laws pertain to cisterns and water.”

Some municipalities—particularly those in remote areas—have issued mandates for reserves. Attitudes are changing as they explore other sources of water. The changes are based on need, Van Giesen states, adding that Tucson, AZ, was the first US city to mandate rainwater collection.

However, to isolate clean water, says Portmann—who represents a pre-engineered steel-bolted tank manufacturing company—you need a tank.

Gauthier believes that, although it has become a critical part of building design, and despite increased demand for various applications, there’s not a lot of new technology in water storage.

The problem is not a lack of new technology, but rather deteriorating old technology. Buddy Key, general manager of inspection, warranty, and maintenance programs for Caldwell Tanks— the oldest and largest tank manufacturer in the world—expresses concern over existing infrastructure. “It hasn’t been paid attention to,” he asserts, adding that much of it is still salvageable if enough focus is given to maintenance.

In business since 1887 and based in Louisville, KY, Caldwell designs, fabricates, constructs, and maintains water towers. “One thing we need is water; it’s a basic need of life,” says Key. “Water is the next oil, and we need vessels to hold our inventory.”

Shakespeare’s Vessel
Shakespeare wrote that an empty vessel makes the greatest sound, but an empty water tank likely signals disrepair. The right vessel is imperative. Options include above- and in-ground, constructed in a wide variety of styles and materials. Typically, the consulting engineer decides on a project decides, Key says, after weighing basic factors that include aesthetics; cost; climate; amount; and frequency of rain, maintenance, capacity, and capacity needs.

Bill Neighbors, president of Tank Connection in Parsons, KS, advises considering other selection criteria, including project design conditions and applicable codes, storage process requirements (agitation, digester, pressure, etc.), system requirements and interface responsibility, corrosion allowance, pH and temperature of stored water, foundation requirements (concrete ring wall with compacted fill, base setting ring, concrete slab, steel bottom with external saddles, etc.), and performance guarantees or warranty requirements.

“Get the specs, review them, and customize for the application,” he suggests. He adds for emphasis, “Get the warranty info up-front, not after the fact, and get it in writing.”

Water tanks constitute a significant investment, as Key points out. With many municipalities and independent companies facing budget constraints and limited funds for repair, it’s vital to get the most for their money.

Neighbors agrees, which is why Tank Connection provides a review of life cycle costs for several products. Life cycle costs are particularly important now, because the trend runs to larger tanks for planned growth and cost-effective maintenance.

“It’s an economy of scale,” he says. “Today’s market is different. Some [tanks] are not less expensive, but they are cheaper. A Tier D [lowest quality] can cost the same as a Tier A [highest quality], but the life cycle costs might be twice as much.”

This is not a throwaway product, he points out. It’s a permanent fixture, and quality is worth the investment.

As a leading designer, manufacturer, and installer offering all types of steel tank construction, Tank Connection views storage tanks and systems as major infrastructure that can last indefinitely with proper maintenance. Believing that the market responds to quality, Neighbors says customers should review and evaluate, adopt the best practices, and make an informed decision.

“The market is educated, but it doesn’t always know about the advances in coatings, et cetera,” he says. “There’s lots of junk offered.”

Even existing tanks are in such disrepair, that Key believes it’s cheaper to buy new. No matter how good an exterior may look, linings and vents may not work properly. “They need to be cleaned periodically,” he instructs.

Whatever the reason for buying a new tank, some general guidelines apply. Van Giesen explains that concrete tanks can be built into the foundation of high-rise buildings, and that the larger the tank, the cheaper the per-gallon storage cost.

Neighbors suggests a bolted tank to meet expedited construction schedules, because it installs in half the time of a welded tank, but adds that sizes over 10 million gallons will lead a customer back to fill welded.

On the other hand, the welding process has changed, Key notes; the way welds are done and checked is more efficient and better overall.

However, Portmann interjects, a welded tank will need recoating every seven to 15 years, to avoid environmental issues.

Other types of tanks are also used, Van Giesen says. Wooden tanks add a designer look, but come with a designer price tag. Molded fiberglass tanks are also expensive, but he considers them one of the best and says they’ll last forever. Fiberglass tanks can be manufactured to store potable water directly without liners or bladders common in both steel and concrete tanks.

Modular tanks have many benefits and polyethylene tanks are increasingly popular. Van Giesen indicates that black is best because it’s the most opaque, which abides by one of his four cardinal rules of water storage that dictate:

* No children—for protection and security

* No light—even a small amount creates algae growth

* No mosquitoes—anti-cistern laws still exist in places like New Orleans

* No tipping over—make sure the foundation is stable and firm

The foundation, however, can also come in a variety of styles. Leg tanks, the most common, are elevated on four to 12 legs, while pedestal tanks have a smaller footprint, because they have a single shaft with a globe on top and fluted tanks feature steel fluted supports under a wide base. Most of them feature a base of steel fabricated on concrete shafts or full welded steel, Neighbors says, adding that Tank Connection holds patents for bolted steel pedestals for elevated tanks.

Slight alterations to the design can help, such as valving or piping inside to distribute water over the full height of the tank or segregating the intake and exit in the riser. Groundwater can regulate water going in with water being used to keep temperatures above freezing. “You have to keep turn in the tank,” emphasizes Key.

Another style Key mentions is a composite tank, featuring a concrete shaft with a welded steel bowl on top. Both fluted and composite tanks hold millions of gallons, he notes, which can lower costs by centralizing the supply.

Steeled for Storage
Not all steel tanks are alike. Varieties include: precision-bolted RTP (rolled tempered panel), welded and hybrid—concrete with a steel bolted side and floor. Size influences the choice: RTP can handle up to 10 million gallons, but for up to 25 million gallons, welded is the better option.

Bolted tanks are modular, which makes them easy to add on to and ship, as well as safer to install, because it can be done at grade level with a jacking process. Like Tank Connections, United Tank Systems also builds from the top down, starting with the roof before constructing the panels, jacking them up, building more panels, and so on.

“It allows us to work at ground level,” explains Portmann. “That adds speed and safety.”

Because the trend is toward bigger thanks, the difference can add up to considerable time savings.

Some factory-welded stainless steel or factory-coated carbon steel tanks are pressure-tested for tightness. The impermeable steel shell is lightweight but strong. “We build all our tanks to UL specifications, whether they’re for fuel, chemicals, or potable water,” points out Gauthier. “The only difference is the internal lining.”

An unprotected tank is susceptible to corrosion, deterioration, and microbial corrosion: It needs protection. Protective linings and coatings form a hard, inert barrier for both interior and exterior surfaces, preventing corrosion. But they have to be matched to the project, Gauthier notes.

For example, he refers to solar hot water tanks that contain 200-plus-degree water: A standard liner would melt. Highland offers the choice of tough, high-solids epoxies, polyurethanes, rubber, PVC, and other sheet linings, all dependent on the project.

“[American Water Works Association] used to rate a 40-year life; now it’s 60–80-plus,” says Neighbors. “It’s more cost-efficient.” Fusion powder coatings from Akzo Nobel—the largest powder coat supplier—are specially formulated for contact with water, with a minimum warranty of five years.

Highland Tank’s HighDRO Liner Plus is composed of a polymer composite for long-lasting flexibility. “We went green,” notes Gauthier. “There are no VOCs [Volatile organic compounds] in polyurethane.”

When it comes to coatings, Caldwell’s  used them all, Key claims. These days, they rely on their own in-house coatings people to paint 80% of their tanks. “Coatings have progressed a lot,” he says.

New epoxy systems contain 100% solids: They’re an expensive application, Key admits, but they provide a hard, long-lasting coating that offers a cost benefit feature.

The reason five years makes such a difference is that the tank has to be shut down for maintenance and pumps used in the interim, which is an expensive and complicated procedure. Key estimates it takes three to four weeks for a total rehab. First, the old interior lining must be blasted off to white metal. The surface must then be prepared, primed, and cured. “You pretty much start from scratch, but with proper protection, the tank will last forever.”

But maintenance is not just painting, he warns. “You could have corrosion or rusted risers that you’d have to replace or rehab. Steel problems are very expensive.”

Alternatives
To avoid some of the issues engendered by steel, United Tank Systems uses Fusion, a glass fused under compression to steel, that is resistant to alkaline, acid (pH), and corrosion. Glass embedded in steel to form a permanent bond is flexible; it doesn’t break. Nor does it have issues with ultraviolet (UV) rays like an epoxy liner. Portmann estimates its design life at 40 years, but says some in municipal service since the 1940s are still being used. Although they can be partially buried, most are installed above ground, which makes construction safer, monitoring easier, and corrosion and leakage less of a concern.

The drawback is cost. Generally within 10% of comparable products, the Fusion’s up-front cost is higher. Portmann attributes the choice to personality, budget and long-term goals—whether the customer wants a quick return on investment or is willing to spend more for a product that will “last forever.”

Another durable alternative to steel is fiberglass. Containment Solutions (CSI) pioneered the technology originally for petroleum. “It’s a ‘wonder material,’” exclaims Heiman. “It doesn’t corrode or rust; it’s watertight—which steel can’t do; it’s durable; it doesn’t dent like steel; it can be patched; it doesn’t need a lining; and it’s the only material that’s paintable.”

The benefit of that applies to both commercial and residential customers. Not only can a tank painted to match a house get around homeowners association (HOA) restrictions, but promotional paint schemes are good advertising. In addition, paint creates an opaque coat that withstands UV rays.

Material isn’t the only decision in the selection process. Heiman says that while new residential units are typically above ground, most commercial and industrial applications feature underground tanks with capacity of 500–60,000 gallons. CSI’s containers can manifold together to match any existing footprint or plan for future growth.

The biggest hurdle is not cost, says Heiman; it’s understanding. Fiberglass is not a new technology, but it is new to this market and it takes time to educate.

A radical green option is the use of recycled plastics. Joe Brown of Roth Global Plastics Inc., a wholesale distributor of irrigation and water systems, considers it the best choice because it takes less equipment to install, lasts “forever”, and is inert and non-reactive, so there are no issues of pH or chlorine. Blow molding technology is used to manufacture the tanks, with a four-layer machine extruding plastic prior to blowing it into a mold. Recycled materials are used for all but the inside layer, which consists of FDA-approved food-grade virgin resins.

Rain, Rain, Don’t Go Away
New materials are being used in new applications. The market is changing, with “gray” the new “green” when it comes to recycling water. Use of graywater and rainwater harvesting are changing the direction of water storage as they ease the burden of treating water to drinking water standards for non-potable use. “Why treat water just to flush it down the toilet?” ponders Van Giesen.

With water management playing an increasingly significant part in the LEED program, earning credits toward the LEED Green Building Rating System is becoming more important. As a member of US Green Building Council, Containment Solutions promotes green building initiatives. “You have to have water efficiency to hit the golden level,” explains Heiman, adding that up to 12 credits can be earned, mostly by limiting potable water use.

It’s a critical move, because the World Health Organization reports that less than 1% of the water on Earth is readily available for human use and consumption. This finite supply of a necessary natural resource makes it clear why conserving potable water is a key focus of green building projects. The use of graywater and rainwater provides a renewable supply of natural, soft water that can be used for a variety of uses, such as fire protection, landscaping irrigation, flushing toilets, laundry, and as emergency backup during power outages and droughts. There are even areas of the world where rainwater still constitutes the primary source of water for all uses.

According to Gauthier, 80% of the water we use doesn’t need to be potable quality, but the US in particular is very wasteful.

Heiman agrees: “We’re using a lot of potable water for non-drinkable needs.”

Municipalities used to battle water storage manufacturers, he claims, because they were considered competition. But that has changed. Water storage is now being promoted as a way to manage flood control and other water issues. “They may lose a little revenue on the front end because of less use, but with less use, they have less to treat,” says Heiman. As he points out, why pay to treat water to a level we don’t need?

Perhaps more significantly, Heiman argues, why not make use of free water, particularly in the face of water restrictions or long dry spells? Rainwater harvesting captures, diverts, and stores rainwater for later use. During a 1-inch rain, approximately 620 gallons of water can be collected for every 1,000 square foot of surface area. That means an average house roof will collect over 1,000 gallons for every inch of rainfall. With proper planning and design, systems can be built to capture up to 100% of the surface area rainwater.

Rainwater is mostly collected from roofs and parking lots and carries different contaminants than gray water, although both can be used for several of the same purposes. Blue Ridge Atlantic Enterprises, which was purchased by Watts in the spring of 2010, is 100% dedicated to rainwater harvesting. “We don’t sell parts and pieces,” says Van Giesen. “We deal in whole systems: storage, pump, filtration, and treatment for commercial and residential customers.”

Rainwater harvesting is not just about water supply: It’s about storm water management, restrictions, and other issues affecting a water-sensitive urban design. We need to completely change the way we look at water, Van Giesen believes.

“We pay to get water, and we pay to get rid of it [our sewer bill],” he says. “We also pay to get rid of free rainwater [storm collection]. Let’s collect and use free rainwater, which also helps manage storm water and moves us away from a one-way path.”

Stormwater collection captures runoff through storm drains built directly into streets and parking lots. Continued urban and residential development has led to increased amounts of impervious surfaces that prevent stormwater from permeating the ground to replenish it,
meaning even average rainfall can cause flooding and dry spells quickly lead to drought. Capture of excess water during rainy periods permits use during drier times.

There’s a fundamental misunderstanding of how water systems work, Brown proclaims. Sewers take water to the ocean, but onsite treatment returns it to the earth as purified groundwater. Sewer overflows in urban areas combined with sanitary sewers (water that needs treatment) undermines the capacity at a treatment facility. By using rainwater and gray water, less water needs to be diverted to treatment facilities. It also means more water is stored for immediate usage.

Some people just want to conserve; others see financial or other beneficial purposes. Master gardeners embrace it because rainwater is soft. However, it’s difficult for the average homeowner to fully irrigate because it takes a big tank to store sufficient amounts. “The financial models aren’t there for homeowners to install rainwater harvesting systems,” says Brown.

In the Southeast, he says, some wealthy people who want to maintain their landscaping when water is not available can do it, but in general, there is little regard for storage or harvesting in residential circles.

There’s more interest on the commercial side because of the Leadership in Energy & Environmental Design (LEED) building movement, but it hasn’t “trickled down to residential acceptance because there aren’t the same financial incentives.” Water is heavily subsidized, Brown states. “The cost is nearly zero in the US. They pay eight to 10 times more per unit in Europe.”

That corresponds with Neighbors’ report that business levels have doubled since 2009, even though the US market is flat and explains the lack of concern for water conservation. But it’s not always about cost. In some areas, such as Colorado, he says it’s illegal to collect rainwater. “In the East, you have riparian water rights: If you own the land, you own the water. In the West, they have claim-based water rights.”

Water rights is the issue, Brown declares, referencing the Great Lakes Compact, a non-binding agreement between eight states and Canada not to sell water from the Great Lakes watershed. “It’s a growing concern, but it’s not mainstream yet.”

Rain barrels are mainstream. They’re the entryway, Van Giesen believes, but they do little more than raise awareness. A tank designed for rainwater collection is necessary. The “next step up from a rain barrel” is a tank with capacity in the 300–1,050-gallon range. Brown has noticed demand for bigger tanks. The cost of doubling the size of a tank is incremental, he says, and as long as you’re putting a tank underground, you might as well dig big.

Highland Tank offers underground and aboveground installation of its newly designed steel collection tanks for rainwater harvesting. An integral part of “green building” that can add LEED points to a project, they are part of a modular filtering and sanitation system that treats the rainwater in its pre-engineered Bio-Basin, water transfer pumps, filtration skid with primary and secondary disinfection, day-tank with non-potable water booster pumps, and state-of-the-art PLC touch screen controller.

“There’s a lot of rain- and graywater potential to supplement water use,” surmises Gauthier. In the Southeast, it’s often used for irrigation, and across the country, it is increasingly used in schools to flush toilets.

With proper planning and design, systems can be built to capture up to 100% of the surface area rainwater.

He mentions a big box store in Ohio that does a lot of irrigation. “They go through 20,000 to 30,000 gallons every couple weeks,” he says. By installing a rainwater harvesting system, they reduced their use of treated water from the municipality. By choosing a Highland system, Gauthier says they achieved a five-year return on investment (ROI), noting that “anything under 10 years is a good investment.”

Another green building project Highland was involved in was the installation of a rainwater harvesting system at the Statute of Liberty. Two 7,500-gallon aboveground tanks capture and store rainwater for use to fuel the heater and to flush the toilets. “We have other projects,” recounts Gauthier. “One in New Jersey, they use it for their cooling tower. In Massachusetts, they use it for dust control. A school in Arizona has two 20,000-gallon pressure vessels for hot water storage used for heating.”

Rainwater and graywater reduce costs and provide security. According to the National Fire Protection Association, the annual cost of fires is approximately $250 billion. Sprinkler systems are recommended—and sometimes required—for emergency fire protection. By using recovered or recycled water, they offer affordable and reliable protection.

Water Words to the Wise
Water collection is simpler and less scary than people think, Van Giesen promises. Depending on the application, there is not necessarily a need for extra plumbing and the water only has to be treated according to its end use.

As Heiman indicates, “The same technology and process can be used for septic systems, fire protection, rainwater harvesting, or grease interceptors. You just change the accessories.”

That refers to new applications only, however; retrofitting for interior rainwater or graywater use is very expensive, because it requires replumbing for a dedicated line. “It’s easier to build new than retrofit,” sums up Gauthier.

Building new allows the customer to size the system accordingly. System design is based on demand, Gauthier explains. “You want 100%. To have that, the system must be big enough to supply fixtures 200% of the time—but if it’s too big, it’s expensive.”

If a tank is too big, Van Giesen adds, water can sit. When it sits, it goes anaerobic. Smoothing the inlet—filling from the bottom for passive mixing without stirring up matte—oxygenates the water to keep it from going septic. It can also be oxygenated with a pump.

Pump technology is ever-changing, Gauthier asserts, adding that pumps can be changed out easily to add new, bigger, better versions. They can also be added onto for

Water storage is now being promoted as a way to manage flood control and other water issues.

additional storage.

“Recycling water keeps it fresh,” says Heiman. The need to recirculate water is why Highland upgraded from building “just” tanks to manufacturing pumps, filters, and disinfection systems.

Gauthier says they thought it was important that the complete package came from one manufacturer. “The average package has four to five components: storage, with size based on the demand and type of use; first flush, because 95% of the contaminants come in the first 15 minutes of a storm, so you want to divert them from the storage area; sediment filters to remove TSS [total suspended solids], sand, grit, gravel, and contaminants; disinfection to remove organic material; and a day tank to hold one day’s worth of water.”

Neighbors agrees that vertical integration is the key to success, which is why Tank Connection buys steel directly from the mill, then
designs, manufactures, delivers, and installs using their own crews. Through single-source responsibility, he believes they offer better safety, quality, and cost savings.

No matter how fresh the water is kept, a full storage tank is no good, Van Giesen advises. “You want to collect and use water wisely.”

“Wise” differs with location, climate, and culture, however. Van Giesen refers to a new law in Florida that requires residents to abandon the septic tank system in favor of the city sewer. He says several are converting their old septic systems to rainwater collection.

Water authorities are reluctant to change and each state has its own code that can be a sticking point with the authorities, Van Giesen reiterates, although he thinks some utilities in the West are beginning to embrace it due to water shortages.

“Rain is one of the best solutions for the future,” he says.

With the price of water on the rise and growing concern over outdated and overused infrastructure, Gauthier believes water storage is the direction the market is headed. “It’s an evolving market, and we’re just scratching the surface of what we need to do.”

Some of the things Gauthier believes we should be doing include staying vigilant about standards and using the right components for durability and reliability. “Some companies use residential components, but they don’t last,” he states. “You need efficient components that last, because the buildings last 30 to 40 years.”

Design life is crucial, Neighbors agrees. “Tanks with short life spans don’t hold up,” he says.

Nor do tanks without proper plate thickness. “The worst thing in the market is web stiffeners to make the tank thinner,” adds Neighbors.

This truss is a reinforced girder or band to support a tank made of thinner material. Portmann says there’s already demand for larger, more durable tanks, and better engineering, and he anticipates a quest for better epoxy coating.

Focusing on priorities and strategically planning and designing for needs and growth is Key’s advice. Anything that’s sustainable has to be recycled.
About the Author

Lori Lovely

Winner of several Society of Professional Journalists awards, Lori Lovely writes about topics related to waste management and technology.

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